Regulation of prostaglandin production in human and experimental hypertension is under study. Prostaglandin A and E levels will be measured in plasma urine, kidney and vascular tissue in a variety of hypertensive conditions and under acute experimental conditions. In vitro studies using rabbit medullary slices and human endothelial and smooth muscle cells in tissue culture will be carried out. The effect of angiotensin I, II, III, norepinephrine and bradykinin on prostaglandin production will be studied.